Yes. In the early days of Baseball this was a common thing to have hapen. There was even a pitcher that pitched a double header and won both by shutout. His name was Ed Reulbach.
JOSE VIZCIANO & LINDY MCDANIEL
"Double" means "Two", so there are two games in a double header.
Jesse Orosco did it on July 31, 1983 against the Pittsburgh Pirates.
Nomo never pitched both games of an MLB double header. After many of his starts, the record shows notation 2. The 2 refers to the 2nd game that day, not both games. But no two of the 323 lifetime MLB games did this power pitcher throw in both ends of a double header.But he may have done so in Japan - maybe the rumor started there?
Alex Bragan, the storied pitcher, pitched a record 14 perfect games in his career.
Jesse Orosco pitched in 1252 games.
a double header